Coin FUN-nel (Funnel) by Royal Magic

Hand the coin funnel out for examination,
and allow a spectator to lock a half dollar inside, separating one
chamber from the other. There's no way anything can pass through the
half dollar. Your spectators are sure of this. The magician then
borrows quarters from his skeptical spectators.

One at a time, and with no sleight of hand at all, the borrowed coins penetrate the half dollar.

The moves are easy to do, and can be mastered in a matter of minutes.

Included is a Kicker Finish by Al Cohen:
Watch their jaws drop when you reveal a battery inside the funnel at
the end of the trick. This is one trick that always sells well.